The present invention relates to delivery devices for prostheses, such as stents, grafts and stent grafts (collectively prostheses) in the vascular system of a patient. In particular, the invention relates to a prosthesis delivery system, device and method that provides the controlled release and implantation of a prosthesis in a controlled manner. In particular, the invention relates to an introducer/delivery device delivery handle that permits controlled release of a prosthesis from the introducer/delivery device.